This invention relates to radial engines in which the cylinders revolve about the crankshaft. More particularly this invention relates to an improved radial engine having an oil reservoir positioned radially outside a cylinder and having its intake fuel mixture compressed by the power stroke of a piston. This relatively powerful light weight engine is ideally suited for use in a helicopter having two rotors, each revolving in an opposite direction about a common axis.
In a conventional rotary engine the oil reservoir is positioned between the rotating cylinders. Centrifugal force tends to draw the lubricating oil into the combustion chamber. This was the primary drawback of the French Ghome engine in the first world war. In addition to smoking, consumption of oil could cause engine failure. This ongoing problem of oil seepage has greatly limited the use of the relatively light weight rotary engine.
In aviation particularly, there is a need great need for a reliable engine having a low weight: power ratio. Anything that can be done to reduce this weight: power ratio should be done. In helicopters, where every pound of load must be monitored because of high fuel costs, there is a particular need for an engine having a low weight: power ratio.
It is an object of this invention to disclose a design for a rotary which reliably solves the problem of lubricating oil being drawn into the cylinders. An engine which does not burn a mixture of fuel and oil. It is yet a further object of this invention to disclose a rotary engine which is super charged thereby resulting in an even lower weight: power ratio. It is a final object of this invention to disclose a helicopter which is designed to utilize this light weight engine. The disclosed design results in an even unexpectedly low weight: power ratio.
One aspect of this invention provides for an improvement in a rotary engine of the type having a block, cylinders generally radially arranged within the block, pistons slidably positioned in the cylinders defining combustion chambers on an inner side portion of the pistons in the cylinders, a central crankshaft, reciprocating piston rods having an inner end crankably connected to the crankshaft and an outer end connected to the pistons, and an oil reservoir, the improvement which comprises: said oil reservoir being positioned radially outwardly from the pistons so that centrifugal force resulting from engine rotation tends to keep oil out of the combustion chambers.
Another aspect of this invention provides for an engine as above further comprising a one way valve and a fuel manifold in the housing and wherein the engine is configured to draw a fuel mixture first through the one way valve into the fuel manifold on a compression stroke of the piston and compress the fuel mixture in the manifold on a power stroke of the piston so that when the piston begins an inlet stroke the pressurized fuel mixture will flow rapidly into the cylinder.
Yet a further aspect of this engine comprises a preferred use for the disclosed rotary engine. A helicopter comprising: an aircraft body surrounding a pilot; a rotary engine having a housing containing an upright crankshaft which has a lower end portion rotatably attached above the aircraft body; a first main lifting rotor centrally attached to an opposite upper end portion of the crankshaft of the rotary engine; and, a second main lifting rotor attached to the housing of the rotary engine so that when the rotary engine is operating the first main lifting rotor is rotated in one direction, and the engine and the second main lifting rotor together tend to rotate in an opposite direction, and a brake mechanism so that the relative rotational speed of the rotors may be controlled by the pilot.
Various other objects, advantages and features of novelty which characterize this invention are pointed out with particularity in the claims which form part of this disclosure. For a better understanding of the invention, its operating advantages, and the specific objects attained by its users, reference should be made to the accompanying drawings and description, in which preferred embodiments of the invention are illustrated.